CN1227161A - How tires are made - Google Patents

Abstract

A method of manufacturing a tire, the steps of manufacturing a carcass layer of a carcass structure are as follows: preparing at least one continuous strip-shaped element; laying the strip-shaped element on an annular table in alternating laying sections to form two side portions and Crown, the two side portions extend axially perpendicular to the plane of the rotating shaft of the annular table top, the crown extends radially outside between the two side portions, and the crown portions of each laying section are continuous along the circumferential direction of the annular table top are laid side by side, wherein the side of each laying section partially overlaps a side of at least one subsequent laying section. The method can improve the production efficiency, simplify the manufacturing process and reduce the production cost.

Description

How tires are made

The present invention relates to a method for manufacturing wheel tires. The method comprises the following steps: preparing a carcass structure; attaching a belt structure to the carcass structure along the outer side of the carcass structure; Externally attaching the tread belt to the belt structure; attaching at least one pair of sidewalls to the carcass structure in transversely opposite positions to the carcass structure; vulcanizing the tire obtained.

The manufacture of tires for vehicle wheels consists in forming a carcass structure which in fact consists of one or more carcass layers, which are annular in nature and whose edges on opposite sides in the axial direction are joined with circumferentially inextensible annular reinforcing elements That is, the so-called "binder core" is in contact.

Attaching a belt structure to the carcass structure along the outer side of the carcass structure in the circumferential direction, the belt structure includes one or more closed endless belts, which actually include a fabric core or a metal core, the fabric core or metal The cores are at suitable angles to each other or to the cores belonging to the underlying carcass layer.

A tread strip, usually comprising a strip of elastic material of suitable thickness, is attached to the belt structure along its circumferential outer side. It should be noted that, for the purposes of the present invention, the term "elastomeric material" means a rubber-incorporated material consisting of a basic polymer combined with suitable mineral additives and/or other additives of any type.

Finally, a pair of sidewalls are attached to the tire on opposite sides of the tire to be produced, each sidewall covering one side of the tire, between the so-called shoulder region and the so-called bead region Between, the so-called shoulder regions are located close to the respective side edges of the tread band, while the so-called blankholder regions are displaced from the corresponding blankholder cores.

The traditional manufacturing method is actually such that the above-mentioned tire components are first prepared separately and then assembled together in the tire manufacturing step.

For example, in order to prepare a carcass layer associated with a blank holder core to form a carcass structure, it is first necessary to prepare a fabric impregnated with rubber liquid by extrusion and/or calendering, the fabric comprising a continuous fabric core or metal core. The fabric impregnated with rubber liquid is subjected to a transverse cutting operation to predetermined lengths to produce a continuous strip-shaped semi-finished product with transversely arranged parallel cores.

Then, the prepared parts are cut into different lengths according to the circumferential lengthening of the carcass to be prepared.

Manufacturing methods have recently been provided which dispense with the storage of prepared semi-finished products and directly prepare the carcass structure in the tire manufacturing step.

For example, the most relevant prior art is cited U.S. Patent No. 5,453,140, which discloses a method and apparatus for the manufacture of a carcass structure, according to which a continuous wire is juxtaposed continuously in the circumferential direction in alternating laying trajectories placed on an annular table whose shape corresponds to the internal shape of the tire to be manufactured.

In more detail, a layer of rubber raw material is covered in advance on the annular platform, and this raw material layer has two functions, namely: conveniently attaching the laid lines and keeping each laying section in a fixed position; An airtight inner lining is formed in the product.

The individual wires drawn directly from a roller contact the sliding elements and onto the movable guide elements operating on the annular table. The movable guide element moves along a sliding track having an advancing segment and a returning segment connected to form an endless moving track in a radial plane of an annular table. Both the advancing section and the returning section are substantially C-shaped in cross-sectional profile about the annular table.

In this way, the guide elements each cover one of the forward and return sections of the slide path, so that the wire is laid on the annular table, forming a U-shaped laying section around the transverse cross-sectional profile of the annular table.

At the moment between the formation of one laying section and the formation of the next laying section, the annular table can be rotated by a predetermined angular step, so that the device can form a new laying section along the length of the already formed laying section. The circumferential direction is arranged side by side.

The pick-up device brings the wire into contact with the end of the laying section just formed with the fork-shaped element, so as to prevent the guide element from being pulled along the latter during the initial formation of the next laying section. The retaining device expediently interacts with the contact element in the transition region between two subsequent laying sections, so that the flash edges adhere to the sides of the annular table top.

The tire obtained by this method of manufacture has a carcass structure in which the core constituting the carcass plies consists of individual linear elements forming a number of consecutive segments across the tyre, each segment extending circumferentially Arranged side by side in parallel and laid in opposite directions to form alternate tracks.

In the context of the manufacture of carcass structures, it is known from European patents EP0664231 and EP0664232 that laying sections formed of individual linear elements are laid axially in alternating directions, with respect to opposite sides of one or more annular anchoring elements For laying, the annular anchoring element comprises said blank-holding core.

According to the invention, different advantages can be achieved within the framework of tire manufacture, the carcass ply is formed by at least one belt-shaped element comprising in fact a layer of raw material of elastic material consisting of two or more parallel longitudinal linear elements arranged in alternating successive segments across the tire.

In more detail, the invention relates to a method for the manufacture of tires for vehicle wheels, characterized in that the manufacture of the carcass structure comprises the formation of at least one carcass ply, the steps of preparing the carcass are as follows: preparing at least one continuous strip-shaped element, the The continuous strip-shaped element comprises several longitudinally parallel linear elements, which are at least partially coated with at least one layer of elastic material raw material; the strip-shaped elements are laid on the annular table in alternating laying sections, each laying section around The transverse cross-sectional profile of the annular table extends substantially U-shaped to form two sides and a crown, the two sides extending axially at mutually spaced positions in a plane substantially perpendicular to the axis of rotation of the annular table , the crown extends radially outward between the two side portions, and the crowns of each laying section are continuously laid side by side along the circumferential direction of the annular table top, wherein the side portions of each laying section are connected to at least one subsequent One side portion of the laying section overlaps.

In more detail, the mutually overlapping relationship of the sides results in mutual convergence in the direction of the geometric axis of rotation of the annular table top.

Advantageously, the sides of the laying sections are placed in a gradually decreasing relation to one another, with a maximum at the radially inner end of said sides, and in the transition region between said sides and crown The stack amount is zero.

In particular, the side portions in overlapping relationship remain connected in the region of the bent end where the strip-shaped element itself is folded.

In a recommended technical solution, the circumferential spacing of each laying section on the annular platform is the width of the strip-shaped element.

In another possible embodiment, the circumferential spacing of each laying segment on the annular platform is a multiple of the width of the strip-shaped element. In particular, the width of the strip-shaped element is measured at the mid-section as a submultiple of the circumference of the annular land.

According to another aspect of the invention, manufacturing said at least one carcass layer further comprises a subsequent step of stretching the belt-shaped elements at the sides of the layup section to form a wider area.

In particular, said stretching step is carried out directly on the strip-shaped element during the laying step, by applying a stretching action to the strip-shaped element upstream of the annular table.

During said stretching step, the linear elements of the strip-shaped elements are also simultaneously moved away from each other.

During the laying step, at least one laying section comprising the initial end of the strip-shaped element can advantageously be held on the annular table by the action of suction produced by the annular table itself.

In particular, forming each laying section comprises the steps of: guiding a strip-shaped element over a distributing element movable around the transverse cross-sectional profile of the annular table; making the distributing element substantially radially away from the geometric axis of rotation of the annular table move to form the first side of the laying section of the strip-shaped element; rotate the annular table relative to the distribution element by an angular step corresponding to half the distribution pitch of the laying section, while forming said first side portion; the distribution element is moved substantially parallel to the geometric axis of rotation of the annular table to form the crown of the laying section of the strip-shaped element; the distribution element is essentially moved radially close to the geometric axis of rotation of the annular table , to form the second side portion of the laying section of the strip-shaped element; the annular table is rotated by the said angular step relative to the distribution element, and at the same time the said second side portion is formed.

In particular, during the formation of the first side of each laying section, the retention of the strip-shaped element at the bend zone formed between said first and second side of the already formed laying section is carried out. step.

For example, this retaining step of the strip-shaped element is carried out in such a way that after the distribution element is radially close to the geometric axis of rotation of the annular table, a retaining element is provided along the second side, so that the strip-shaped element wraps around the retaining element The foldback, thus, forms a curved region due to the distributing element moving radially away from the geometric axis of rotation of the annular table.

Also in particular, after starting to form the crown of the laying section in preparation, the retaining element should be disengaged from the bending region in the axial direction.

A step of abutting said side of the laying segment against the side wall of the annular table can also be performed.

In particular, this abutment step is repeated for the first and second sides of two consecutive laying sections.

Advantageously, forming the carcass structure also includes the step of attaching at least one inextensible annular structure in a region close to each circumferential inner edge of the carcass layer obtained in the laying step.

Forming the carcass structure may also include the step of turning back the side flashes around each inextensible annular structure.

According to another novel aspect of the present invention, it can also advantageously be adapted independently of the novel features listed above, to form each inextensible annular structure, comprising the steps of: laying at least one linear element in a mold cavity Coiled concentrically to form a circumferentially inextensible annular insert positioned substantially parallel to the side of the carcass layer; an annular anchoring element is positioned within the mold cavity at a position axially adjacent to Circumferentially non-extensible annular insert; raw materials of elastic material are injected into the mold cavity to form a pouring body, which is tightly combined with the annular anchoring element and the circumferentially inextensible annular insert.

Said laying step can conveniently be carried out before the step of immersing in rubber liquid, in which said linear element is laid with at least one layer of raw material of elastic material.

In particular, there may also be the step of magnetically retaining the circumferentially inextensible annular insert at a predetermined position within the mold cavity.

The injection of the raw material of the elastomeric material can advantageously take place through at least one circumferential inlet or hollow channel which communicates with the mold cavity.

According to a possible embodiment, forming the carcass structure further includes the step of forming the second carcass layer in the same manner as the first carcass layer.

According to another aspect of the present invention, completely independent of the above description, the application of the belt structure comprises the steps of: forming at least one continuous strip comprising at least one layer of raw material of elastic material at least partially comprising several a longitudinally parallel core; cutting said continuous strip at a predetermined angle with respect to the longitudinal direction to form strip sections having a predetermined width when measured perpendicular to the cutting direction; laying the strip sections continuously in circumferential alignment on The carcass is structurally formed to form at least one first continuous strip having said core arranged transversely at an inclination angle corresponding to the cutting direction of said strip segments.

Before said cutting step, the continuous strip may be subjected to a calendering step such that said strip segments have a circumferential dimension corresponding to a submultiple of the strip's circumferential dimension.

In particular, affixing the tape structure also includes the step of forming at least one second tape by winding at least one continuous linear element into coils, the coils being axially juxtaposed and positioned relative to the first tape along the Circumferential extension.

If necessary, the coils formed by winding the elongated element can have a variable spacing between them in the axial direction, for example, the spacing near the mid-section of the annular table is greater than the spacing between the two side edges of the belt structure.

Advantageously, attaching the tread band may include the step of: stacking at least one continuous layer of elastic material stock circumferentially around the band structure to form several radially stacked rings.

In particular, said continuous layer of elastic material is produced simultaneously with the attachment to the belt structure.

Advantageously, the width of the layer of elastic material gradually decreases while being wound around the tape structure in a ring shape.

According to another independent aspect of the present invention, each of said side walls is preferably formed by injecting a resilient material into a mould.

In more detail, forming each side wall includes the steps of: injecting a first elastic material into a first cavity formed in said mold to form a radially outer portion of the side wall; forming a second cavity in the mold, which A radially outer portion of the sidewall is defined in part; and a second elastomeric material is injected into a second cavity of the mold to form the radially inner portion of the sidewall.

Before forming the carcass layer, a step may be carried out: laying at least one layer of air-impermeable elastic material on the annular platform.

The laying step is preferably carried out by winding at least one strip of gas-impermeable elastic material into rings, the rings being in juxtaposed relationship along the transverse cross-sectional profile of the annular table.

Additionally or instead of forming an air-impermeable layer, prior to the vulcanization step, the following steps are carried out: removing the tire from the annular table; inserting the air tube into the carcass structure.

During said vulcanization step, said carcass plies and belts are preferably subjected to a stretching step in order to generate tension in the tire to inflate the tire to a linear elongation of between 2% and 5%.

Other characteristics and advantages of the present invention will be best understood from the following detailed description of a suggested but not limited embodiment of a method of manufacturing a tire for vehicle wheels according to the present invention. This explanation is carried out in conjunction with accompanying drawing, but not limited to embodiment, accompanying drawing includes:

Figure 1 is an anatomical partial perspective view of a tire according to the invention;

Figures 2 and 3 show the device for preparing the carcass ply, in various operating steps, showing the direction perpendicular to the diametrical section of the annular table on which the tire is loaded during its manufacture;

Figure 4 is a schematic view of the preparation of strip-shaped elements for forming carcass layers;

Figure 5 shows an embodiment of the strip-shaped element in transverse section;

Figure 6 is a partial perspective view of the sequential laying of belt-shaped elements for laying carcass layers according to the present invention;

Figure 7 is an exploded diametric cross-sectional view of an inextensible annular structure inserted at the bead of the tire during the molding step of making the tire;

Figure 8 is a partial perspective view of an inextensible annular structure laterally attached to a carcass layer;

Figure 9 is a schematic diagram of forming a continuous strip and cutting it into a predetermined shape and size for preparing the first strip;

Figure 10 is a transverse sectional view of the continuous strip;

Figure 11 is a partial perspective view of a tape segment being laid in circumferential alignment on the carcass structure for forming said first tape;

Fig. 12 is a schematic diagram of preparing linear elements impregnated with rubber liquid for preparing the second belt;

Figure 13 is a partial perspective view of the step of forming said second band from continuous linear elements;

Fig. 14 is a schematic diagram of forming a continuous layer of elastic material for the preparation of tread bands;

Fig. 15 is the partial perspective view that is wound into several superimposed rings by continuous layer and prepares the tread band;

16 is a schematic cross-sectional view of forming a tire sidewall;

Figure 17 is a partial perspective view of attaching the sidewall to the tire during the manufacturing process;

Fig. 18 is a partial perspective view of the tire having an inextensible annular structure prepared according to another possible embodiment of the present invention;

Fig. 19 is a transverse half-sectional view of a tire according to the present invention mounted on a corresponding hub and in a state of sliding rotation.

Referring to the drawings, in particular FIGS. 1 to 17 , a wheel tire manufactured according to the method of the present invention is generally indicated by the code 1 .

The tire 1 mainly comprises a carcass structure 2, which has at least one carcass layer 3, the carcass layer 3 is annular in nature, and the two circumferential edges of the carcass layer 3 are mutually connected with an inextensible annular structure 4, respectively. Joining, when the tire is made, the annular structure 4 is located at what is commonly called a "bead".

On the circumferential exterior of the carcass structure 2 is attached a belt structure 5 comprising one or more strips 6 , 7 . The tread portion 8 is circumferentially superimposed on the belt structure 5 and has longitudinal and transverse grooves 8a in the tread portion 8 provided to define the ideal "tread pattern".

The tire also comprises a pair of so-called "sidewalls" 9 attached transversely to opposite sides of the carcass structure 2 .

The inner side of the carcass structure 2 can also be coated with an airtight layer of elastic material 10, the so-called "liner", which essentially includes a layer of airtight elastic material, suitable for ensuring the air pressure of the pneumatic carcass. Tightness.

The assembly of the above-mentioned elements and the manufacture of one or several of the above-mentioned elements are carried out on the annular table 11, as shown in Figures 2 and 3, the shape of the annular table 11 is the same as that of the inner wall of the tire to be manufactured.

In a recommended technical solution, the size of the annular table 11 is smaller than the size of the product tire, which is based on the fact that the circumference of the annular table itself has a linear elongation along the middle facet X-X, in particular, the elongation is between 2% and Between 5%, the middle split plane of the annular table coincides with the middle split plane of the tire itself.

The annular table top 11 is not described in detail or shown, because it is not particularly important to achieve the purpose of the present invention, for example, the annular table top 11 includes a deflated drum or an inflatable bladder, which is suitable for Produces and maintains ideal ring shape.

Taking into account the above, the manufacture of the tire 1 begins with the formation of the carcass structure 2 , preceded by the formation of the possibly air-impermeable liner 10 .

The liner 10 is preferably wound circumferentially around an annular table 11 with at least one strip 12 of gas impermeable elastic material produced by an extruder or calender adjacent to the annular table. It can be seen from FIG. 1 that the wrapping of the belt 12 is essentially a circumferential ring, and each ring is arranged side by side sequentially along the transverse cross-sectional profile of the outer surface of the annular table 11 .

For the convenience of description, the so-called "transverse section profile" refers to the shape of the half section of the annular table taken from a plane radially passing through the rotating shaft of the annular table. The rotating shaft of the annular table is not shown, and it is related to the The geometric axes of rotation of the tire coincide.

Simultaneously with the winding of the belt 12, a pair of auxiliary annular elements 12a are affixed during the manufacturing process adjacent to the inner circumferential edge of the carcass structure. Each auxiliary annular element 12a can be obtained, for example, by winding a band 12 into an annular band positioned axially adjacent to a corresponding annular band at the inner periphery of the liner 10 . In addition, the auxiliary annular element 12a may consist of at least one auxiliary strip obtained from a corresponding extrusion machine located on the annular table 11 .

According to the invention, the carcass layers 3 are laid directly on the annular table 11 along alternating tracks, at least one strip-shaped element 13 preferably having a width between 3 and 15 mm, as will become clearer below.

As shown in Figure 4, the strip-shaped element 13 essentially comprises two or more, preferably three to ten linear elements 13a fed by corresponding rollers 14, the strip-shaped element 13 should be produced by the first extruder 15 is prepared in a guided manner, a first extruder 15 is associated with a first extrusion device 16 which feeds the raw material of the elastic material through the extruder.

It should be noted that in the present invention a so-called "extruder" is a part of an extrusion device, and in a particular field the term "extrusion head" is also used, which has a so-called "die" with an outlet through which the product passes , the shape and size of the mold conform to the geometric and dimensional characteristics of the product to be prepared.

In the extruder 15, the elastic material and the linear elements 13a are intimately bonded together, thereby producing a continuous strip-shaped element 13 at the exit of the extruder, which comprises at least one layer of elastic material 13b, the elastic material The thickness of the layer 13b includes the linear element itself.

If desired, the linear elements 13a can be guided in the extruder 15 in such a way that the strip-shaped elements 13 are not all included in the layer of elastic material 13b, but are exposed on both surfaces.

For example, each linear element 13a may comprise a fabric core or a metal core, in particular a fabric core with a diameter between 0.6 mm and 1.2 mm and a metal core with a diameter between 0.3 mm and 2.1 mm.

If desired, the linear elements 13a are preferably arranged within the belt-shaped elements 13 in such a way that the carcass layer 3 is very compact and homogeneous. For this purpose, for example, the linear elements 13a are arranged at a density of up to 6 linear elements/cm in the circumferential direction on the carcass layer 3 adjacent to the mid-section plane X-X of the tire 1 . In any case, the linear elements 13a are preferably disposed within the strip-shaped elements 13 in such a manner that the distance between the centerlines of the linear elements 13 is not less than 1.5 times the diameter of the linear elements 13, so that in adjacent linear elements Appropriate dipping in rubber liquid can be performed between them.

The strip-shaped element 13 emerging continuously from the extruder 15 is preferably guided on a laying device 18 optionally via a first collection compensating device 17 , as shown in FIGS. 2 and 3 .

The laying device 18 essentially comprises a first guide element 19 comprising, for example, a pair of rollers supported on static rotating shafts, which are in contact with the continuous strip-shaped element 13 produced by the extruder 15 . Downstream of the first guide element 19 , the strip-shaped element 13 comes into contact with a second guide element 20 , for example, which further comprises rollers mounted on a carriage 21 which can move along the center of the annular table 11 . The transverse direction of the facet reciprocates. At least one distributing element 22 is slidably connected to the movable carriage 21 in a direction substantially perpendicular to the direction of movement of the carriage, for example, the distributing element 22 may also comprise further rollers.

The elements that make the connection and movement between the distribution element 22 and the movable carriage 21 are not shown in the drawings, because they can be manufactured in any convenient way for those skilled in the art, in any case, for It is not important to achieve the purpose of the present invention.

Through the combination of the transverse movement of the carriage 21 and the radial movement of the distribution element 22, the distribution element can be reciprocated along a trajectory "t", which along the transverse cross-sectional profile of the annular table 11 is substantially U-shaped.

The annular platform 11 can be driven to rotate step by step while the distributing element 22 moves. The specific mode is that the belt-shaped element 13 is laid on the annular platform with continuous laying segments 23, 24 along the transverse direction of the tire. Each laying segment 23, 24 The rows are arranged parallel to each other along the circumference, and the directions of laying are opposite, thereby defining alternating trajectories.

In more detail, each laying section 23, 24 extends in a U-shaped direction along the transverse cross-sectional profile of the annular platform 11 to define two side portions 23a, 23c, 24a, 24c and crown portions 23b, 24b, which 23a, 23c, 24a and 24c essentially extend in axially spaced planes perpendicular to the axis of rotation of the annular table top, while crowns 23b, 24b extend radially outwardly relative to the portions 23a, 23c, 24a and 24c on both sides. position extension.

For convenience of description, the laying section obtained by moving the laying element 22 from right to left as shown in FIGS. 2 and 3 is hereinafter referred to as the first laying section 23 . Conversely, the laying section resulting from the transverse movement of the distribution element 22 in the opposite direction is referred to as the second laying section 24 .

In more detail, the laying sequence of the strip-shaped elements 13 on the annular table 11 is as follows.

Assume that starting from an initial state, as shown in FIG. 2 , the distributing element 22 is in the lowermost position to the left of its trajectory "t". From this position, the distribution element 22 is moved essentially outwards in a radial direction with respect to the geometric axis of rotation of the annular table 11 to form the first side 23 a of the first laying section 23 .

The adherence of the raw material of the elastic material covering the layer 13b of the linear elements 13a ensures a stable attachment of the strip-shaped elements 13 to the surface of the annular table 11 even when there is no liner 10 on the annular table 11. In this case, as shown in FIGS. 2 and 3 , the annular table 11 has a side portion 11 a of concave profile located at a position corresponding to the sidewall of the tire to be manufactured, once the belt-shaped element 13 along the The above-mentioned sticking takes place when the radially outer side of the transverse cross-sectional profile of the annular table is in contact with the annular table.

In addition to utilizing the inherent adhesiveness of the elastic material, or without the inherent adhesiveness of the elastic material, the strip-shaped element 13 can also be retained on the annular table 11 by adsorption. One or several suitable holes 28 are realized.

In the initial phase of the distributing element 22 away from the axis of rotation of the annular table 11, the strip-shaped element 13 is folded over itself to form a curved area 25, which is the first side 23a of the laying section 23 to be formed and the laying already formed. The transition between the second side 24b of the segment 24. During the formation of the first side portion 23a, the strip-shaped element 13 may be conveniently retained in said curved region 25 by retaining elements 26 (FIG. 3) which are in contact with the curved region in a manner hereinafter Be more explicit.

Simultaneously with the formation of the first side portion 23a, the annular platform 11 is turned relative to the distribution element 22 about its own rotational axis by an angular step which is half the circumferentially distributed step of the laying sections 23 , 24 . Therefore, the formed first side portion is correspondingly inclined by an included angle with respect to the direction in which the distribution element 22 is away from the geometric axis of rotation of the annular table top.

In the embodiment shown in FIG. 2 , the circumferential spacing of the laying segments 23 , 24 corresponds to the width of the strip-shaped element 13 , while the rotational angle step of the annular platform 11 is half the width of the strip-shaped element.

In any case, the circumferential spacing of the laying segments 23 , 24 can correspond to a multiple of the width of the strip-shaped element 13 . In this case, the angular step of rotation of the annular table 11 corresponds in any case to half the step of the circumferential distribution. It should be noted that for the purposes of the present invention, the term "circumferential" refers to the circumference located on the mid-division plane X-X and adjacent to the outer surface of the annular table 11, unless otherwise specified.

When the dispensing element 22 is adjacent to the furthest point away from the geometric axis of rotation of the annular table 11 , the movable carriage 21 moves in a direction from left to right as shown in FIG. 2 . In this case, the direction of movement of the distribution element 22 is essentially parallel to the geometric axis of rotation of the annular table 11 in that the crown 23 b of the laying section 23 being produced is formed radially outside of the latter.

When the carriage 21 has substantially completed the transverse movement, the distribution element 22 substantially approaches the geometric axis of rotation of the annular table 11 in the radial direction. In this case, the second side portion 23c of the first laying section 23 is formed.

Simultaneously with the formation of this second side portion 23c, the annular table top 11 is rotated relative to the distribution element 22 according to the aforementioned rotation angle steps.

When the distributing element 22 will complete the lateral movement and approach the geometric axis of rotation of the annular table, another retaining element (not shown) will be in place along the newly formed second side portion 23b, which is identical to the above-mentioned retaining element. The bit elements are the same, and they are arranged in a mirror image relationship, as shown by the dotted line in FIG.

In particular, the retaining element 26 then approaches the annular table 11 laterally, so that the distributing element 22 can pass during the upward movement, so that while the first side 24a of the new second laying section 24 is being formed, the belt-shaped The element 13 returns around the retaining element so that a new bending zone 25 is formed.

While forming the first side portion 24a of the new second laying section 24, the annular table 11 performs a new rotation angle step, plus the previous laying of the second side portion 23b forming the new first laying section 23 The angular stepping carried out during the process prepares the distribution element 22 to be formed on the crown 24b of the second laying section 24 at a position spaced apart from the above-mentioned laying section 23 according to the desired circumferential distribution pitch.

After the formation of the crown 24b has started, the retaining element 26 is axially disengaged from the curved region 25 . In fact, during this process, it can be ensured that the strip-shaped element 13 comes into contact with the surface of the annular table 11 downstream of the first side portion 24a just formed and is not prone to undesired displacements that could damage the strip. laying geometry of shaped elements.

Once the retaining element 26 has been disengaged from the bending region 25 , the side portions 23 c , 24 c of the laying segments 23 , 24 can proceed to the stage of abutting against the side walls of the annular table 11 . To this end, a pair of press rollers 27 or equivalent elements may be provided to operate on both sides of the annular table 11, each press roller being arranged in such a way that it can be applied to the first and second sides of the adjacent laying section. Repeated operations.

Only one pressure roller 27 is shown in FIG. 3 .

As a result of the operation of the above-mentioned laying device 18, on the obtained carcass layer 3, the crowns 23b, 24b of the respective laying sections 23, 24 are continuously arranged side by side along the circumferential direction of the annular platform 11, and the crowns 23b, 24b of the respective laying sections 23, 24 The sides 23a, 23c, 24a, 24c are in overlapping relationship with the sides of at least one continuous laying section. More specifically, the first side portion 23 a , 24 a of each laying section 23 , 24 partially overlaps the second side portion 23 c , 24 c of the already formed laying section 23 , 24 .

As can be clearly seen from Fig. 6, the mutual overlapping relationship of the side portions 23a, 24c is essentially all pointing to the geometric axis of rotation of the annular table top 11, and the included angle between the two is δ, which is related to the following data, namely : the width "L" of the strip-shaped element 13, the circumferential distribution pitch of the laying sections 23, 24 in any case, the maximum and minimum radius R' corresponding to the maximum and minimum distance of the annular table 11 respectively difference.

Due to the mutual convergence of successive first and second side portions 23a, 24c and 24a, 23c, their mutual overlap gradually decreases from a maximum at the radially inner ends of said side portions, wherein said The sides meet each other at the curved region 25, and the overlap in the transition region between the sides and the crown 23b, 24b may be zero,

It should be noted that due to the difference in the minimum and maximum radii R and R', the average density of the linear elements 13a, i.e. the amount of linear elements in the circumferential direction within a given length, in the direction approaching the geometric axis of rotation of the annular table 11 tend to increase gradually. This increase in density is proportional to the ratio between the largest radius R' and the smallest radius R.

However, in a tire manufactured according to the invention, the mutual superposition between the sides 23a, 24c and 24a, 23c makes it possible to obtain an average density at the circumferential inner edge of the carcass layer 3, i.e. cut in half.

In this case, the curved areas 25 are connected to each other in the circumferential direction, so that the distribution of the linear elements 13a along the circumferential inner edge of the carcass layer 3 is uniform, provided only that the ratio between the largest radius R' and the smallest radius R corresponds to 2.

On the contrary, as often happens, when the ratio between the maximum radius R' and the minimum radius R is less than 2, the curved portion 25 tends to be arranged such that the circumferential distribution pitch is greater than the width of the strip-shaped element 13, therefore, in a curved Between the region 25 and the other curved region 25 there is a gap.

If such voids are to be prevented in order to achieve maximum structural homogeneity of the carcass layer 3 adjacent to its circumferential inner edge, the invention provides a step of stretching the strip-shaped element 13, compressed The extended portion corresponds to the longitudinal extension area of the side portions 23a, 23c, 24a, 24c, thereby defining the area of increased width L' of the strip-shaped element, which will be located in the circumferential direction of the formed carcass layer 3. inner edge.

Said stretching operation can be done by pressure rollers 29, for example, pressure rollers 29 can be mounted on a movable carriage, suitable for selectively acting under the action of a drive 30, so as to press the strip-shaped element 13 against the On a roller of a part of the second conveying device 20.

The drive 30 is sequentially driven during the laying of the strip-shaped element 13 to longitudinally stretch the portions of the strip-shaped element 13 which will form the sides 23a, 23c, 24a, 24c. The thrust of the actuator 30 can be conveniently measured, for example, a gradually increasing thrust is obtained in a direction approaching the bending region 25 and a gradually decreasing pushing force is obtained in a direction away from the bending region 25 . The stretching operation reduces the thickness of the elastic layer 13b and increases the width of the strip-shaped elements 13, which in turn causes the linear elements 13a to move away from each other.

By conveniently measuring the thrust applied by the actuator, the width of the strip-shaped element 13 can be increased to L' so that each bending zone 25 matches the adjacent bending zone.

By inclining the geometric axis of rotation of the annular table 11 at an appropriate angle relative to the direction of movement of the movable carrier 21, the crowns 23b, 24b of the laying sections 23, 24 can be ideally positioned relative to the radial plane passing through the geometric axis of rotation of the annular table. The angle of inclination is particularly between 0 and 15 degrees, more particularly 3 degrees. It should also be noted that since the rotational stepping of the annular table 11 and the formation of each laying section 23, 24 are carried out simultaneously, the sides 23a, 23c, 24a, 24c of the laying sections will Inclined at an angle of δ/2, the inclination direction of the first side portions 23a, 24a is opposite to the inclination direction of the second side portions 23c, 24c.

Completion of the carcass structure 2 generally includes the step of affixing said inextensible annular structure 4 adjacent to the circumferential inner edge of the carcass layer 3 in a manner as described above, so as to produce a so-called "binder" The carcass area, thereby ensuring the retention of the tire on the corresponding mounting hub; according to a preferred embodiment of the tire, the carcass layer can be obtained as described above.

Each inextensible annular structure 4 ( FIG. 7 ) comprises an annular anchoring element 31, commonly referred to as a "binder core", which may for example consist of one or more metal wires which may Twisted together, or wound into loops abutting together, such that their cross-sectional profile is circular or quadrangular in nature.

According to a preferred embodiment, the advantage associated with the invention is also that the circumferentially inextensible annular insert 32 is combined with the blanking core 31, substantially in a plane parallel to the surface of the adjacent carcass layer 3 Extension, the amount of elongation in the radial direction is determined by the difference between the smallest inner radius and the largest outer radius of the annular insert. In particular, equal to at least twice the radial extension of the blank holder 31 , or in any case greater than the latter.

In a first embodiment as shown in FIGS. 1 , 8 , 15 , 17 and 19 , the inextensible annular insert 32 is located axially on the outside of the blank holder core 31 . In other words, the inextensible annular insert 32 is located laterally on the side of the blank-holding core 31 away from the mid-parting plane X-X.

On the contrary, in another possible technical solution as shown in FIG. 18 , the inextensible annular insert 32 is located axially inside the blank-holding core 31 , that is, on the side close to the middle split plane X-X. In this case, the inextensible annular insert 32 extends preferably essentially in contact with the adjacent carcass layer 3 .

The inextensible annular insert 32 is formed from at least one metal core, each metal core being substantially concentric coils 32a. The concentric coil 32a may be defined by a continuous helix, or by individual metal cores forming concentric toroidal coils.

During tire use, the inextensible annular insert 32 has the advantage of being adapted to interact effectively with the bead to tend to rotate about the transverse cross-sectional profile of the bead core 31, which is in direct parallel to the axis of rotation of the tire 1. generated under the action of sliding thrust. This tendency to turn is especially pronounced when the tire is partially or fully deflated.

In particular, to make each annular structure 4, the inextensible annular insert 32 is first placed in the mold cavity 34 formed by the molds 34a and 34b, and at least one linear element in the concentric coil 32a is placed in abutting relation to each other , so that they gradually increase in diameter circumferentially around their geometric winding axis, which coincides with the axis of rotation of the tyre.

The operation of winding the linear element has the advantage that the linear element can be wound in an annular seat in the first die 34a of the dies 34a and 34b, which can be driven in rotation about its own geometric axis of rotation for this purpose.

The advantage of the step of placing the linear elements is that it facilitates the step of impregnating the rubber liquid, so that the linear elements, especially of metallic material, are covered with at least one layer of raw material of elastic material, besides ensuring a good rubber-metal bond of the linear elements In addition, the adhesion to be stably placed in the above-mentioned annular seat is also improved.

The first mold 34a can also be made of magnetic material, or driven electromagnetically, to attract and hold the linear element, thereby ensuring stable positioning of the coil 32a thus produced.

Then, the blank holder 31 is placed in the cavity 34, and then the cavity 34 is closed by closing the first mold 34a on the second mold 34b. Then, a raw material of elastic material suitable for forming an infusion body 33 is injected into the mold cavity 34 in close engagement with the blank holder core 31 and the circumferentially inextensible annular insert 32 .

In particular, injection of the mold cavity 34 is by means of at least one annular injector comprising an inlet or hollow space 35 extending essentially in the circumferential direction of the mold cavity. In this way, the injection into the mold cavity 34 can be done quickly and uniformly, without the risk of stratification phenomena, which would occur if the elastomeric material were forced to be injected through the inlet due to the reduction in cross-section. It should be noted that the inlet space 35 may comprise several openings uniformly distributed along the entire circumference of the mold cavity 34, in any case allowing a quick and uniform injection into the mold cavity.

The production of the inextensible annular structure 4 can be done close to the annular table 11, said structure can be picked up and applied laterally to the carcass layer 3 by suitable mechanical handling means, which are not shown, since they It is not important for the purposes of the present invention.

In particular, after the non-extensible annular structure 4 is attached, no matter which carcass layer, within the scope of the present invention, the side portions 23a, 23c, 24a, 24c of the laying sections 23, 24 have respective radial The flash against the inextensible annular structure 4 is directed towards the geometric axis of rotation of the annular table 11 . These flash edges are substantially close to said bending region 25, and as shown in FIG. 8, these flash edges can be folded back around the inextensible annular structure 4.

For example, this step of turning back can be performed by an air-filled cavity associated with the annular table 11 or a substitute thereof. The amount of extension of the flash edge or the width of the folded-back flash edge can be easily set in advance by appropriately adjusting the radial movement amount of the distributing element 22 or the radial position of the retaining element 26, thereby adjusting the side portion 23a in the radial direction , 23c, 24a, 24c width.

The forming of the carcass structure 2 may include forming and injecting an auxiliary carcass layer, which is not shown in the figures. This auxiliary carcass layer can be superimposed directly on the carcass layer 3 and the inextensible annular structure 4 in the same way as the main carcass layer, in particular forming such laying sections, which are laid in a direction perpendicular to the formation of the first carcass Direction of laying sections 23 , 24 of layer 3 .

At the radial position of the tyre, the belt structure 5 is simultaneously attached to the carcass structure 2 .

The application of the belt structure 5 has the advantage that it can be applied in a new and inventive way essentially directly on the carcass structure 2 which, in a preferred embodiment of the invention, can be produced by the method described above.

To this end, as shown in FIGS. 9 and 10 , at least one continuous strip 36 comprises several longitudinally parallel cores 36 a, for example, made of metallic material, the cores 36 a at least partially comprised in one or several layers. Inside the raw material of the elastic material.

For example, the continuous belt 36 can be realized by the guidance of cores 36a fed by respective rollers 37 and through a second extruder 38 into which the elastic material flows from a second extruding device 39 . The continuous belt 36 from the second extruder 38 also passes through the cutting machine 41 after passing through the first calender roll 40, and the continuous belt 36 is cut off with a given inclination angle α with respect to the longitudinal direction to form a belt section 42, which is vertically The width of the strip segment 42 corresponds at least to the width of a first strip 6 obtained on the carcass structure 2 , measured in the direction of the cutting direction.

The belt segments 42 are placed successively on the carcass structure 2 in circumferential alignment and in juxtaposed relation to each other along respective adjoining edges 42 a parallel to the core 36 a corresponding to the longitudinal edges of the belt 36 .

The installation of the band segments 42 thus forms a circumferentially continuous arrangement of the first bands 6 . As shown in FIG. 11 , in the first tape 6 , the cores 36 a are arranged laterally according to an inclination angle corresponding to the cutting direction of the tape segment 42 .

In particular, the angle of inclination is 80 degrees, in any case between 45 and 90 degrees with respect to the circumferential direction, in opposite directions of inclination with respect to the underlying carcass layer 3 .

In order that the first strip 6 with strip segments 42 of the same direction can be evenly aligned circumferentially, measured parallel to the cutting direction, the transverse dimension of the continuous strip 36 from the second extruder 38 is the circumference of the first strip. Approximate to the dimension. In addition, the transverse dimension can also be slightly smaller than the above-mentioned divisor, and this dimension can be appropriately increased under the calendering action of the roller 40 .

Thus, by intervening appropriately with the calendering rolls 40 , the continuous belt 36 can be made such that the dimensions of the belt segments 42 correspond to submultiples of the circumference of the belt 6 to be produced, without changing the required extruder 38 .

It should be noted that, under the effect of calendering, the distance between the cores 36a increases and at the same time the width of the continuous strip 36 also increases, in any case the distance between the cores 36a remains the same.

If one or more other first bands are to be formed, although not shown in the accompanying drawings, the above-mentioned operation process can be repeated in the same manner, if necessary, between the cores 36a of each first band 36 or between the cores 36a of adjacent bands. The cores 36a may extend oppositely in the crossing direction.

The first band or strip 6 can be formed in a known manner before attaching two strip-shaped inserts 43 adapted to support the edges on both sides of the first strip, so that the latter maintains an essentially flat transverse section. contour.

Thus, at least one second band 7 is produced, in particular by winding at least one continuously extending element 44 , each second band 7 being axially juxtaposed in a ring extending circumferentially around the first band 6 .

If necessary, the winding coils formed by the elongated elements 44 are arranged side by side with a variable distribution pitch along the axial direction, for example, the distribution pitch is larger at the middle split plane X-X of the tire relative to the two side edges of the belt structure 5 .

As shown in Figure 12, in order to prepare the continuous elongated element 44, the cores 44a of one or several elements fed by the corresponding rollers 45 are combined in parallel when passing through the third extruder 46 and subjected to the operation of impregnating the rubber liquid, The third extruder 47 supplies the elastic material to the third extruder 46 .

The elongated element 44 thus obtained has one or more element cores 44a covered with a suitable thickness of elastic material and, after passing through the storage means 48 , is ready to be wound on the first belt 6 .

In a convenient embodiment, said core is a metal core of the well-known HE type (high elongation), the use and characteristics of which have been extensively described, for example, in the applicant's European Patent No. 0461464.

In more detail, these cores comprise a given number of strands each comprising a given number of metal wires having a diameter not less than 0.10 mm and not more than 0.40 mm, in particular, between 0.12 mm and 0.35 mm. The wires in the strands and the strands in the core are all helically wound together in the same direction, and the winding pitch of the wires and strands is the same and uniform.

In particular, these cores are made of high carbon steel (HT) wire, ie with a carbon content not lower than 0.9%.

In a particular embodiment, particularly in the case of truck tyres, it is advantageous that each of said helically wound cores is of the well-known mutual helically wound type 3 x 4 x 0.20 HEHT, the notation denoting : A metal core includes 3 strands, each strand includes 4 metal wires with a diameter of 0.20mm, and each wire is wound into strands in the same direction; as is well known, the abbreviation HE means "high stretchability"; the abbreviation HT means " high tension".

These cores have a stretch rate between 4% and 8% and are known to have typical stretch resistance properties, so called "spring properties".

In another embodiment, particularly suitable for car tires, said wrapping is performed by a fabric core, in particular, the fabric is of heat-shrinkable material, such as nylon material NYLON6 or NYLON66.

Then, the tread tape 8 is attached to the obtained tape structure 5 in the manner described above.

In more detail, according to another aspect of the present invention, the tread belt 8 is formed directly around the belt structure 5 by wrapping at least one continuous layer of raw material 49 in the circumferential direction, as shown in FIG. 15 , the belt The structure has several superimposed rings in the radial direction.

A continuous layer of elastic material can be formed with the help of a fourth extruder 50 , the elastic material being supplied by a fourth extrusion device 51 . The layer 49 from the fourth extruder 50 is further calendered by a calendering device 52 , just downstream of the calendering device 52 , where the annular table 11 for tire manufacture is provided, so that the layer of elastic material is wound directly on the belt structure 5 .

Through the cutting means associated with the calendering means 52 and/or through the gate means at the outlet of the fourth extruder 50 (neither means are shown, because the person skilled in the art can do it by any convenient means) , while the winding structure 5 forms each winding ring "S", it can facilitate the gradual reduction of the width of the elastic material layer 49, and the width of each elastic material layer gradually decreases in the direction away from the rotation axis of the tire 1. As shown in Fig. 15, it can be easily deduced that the width of the radially outer ring "S" is smaller than the width of the radially inner ring so that the tread band 8 has the desired transverse profile.

After the tread strip 8 is attached or optionally before this operation step, the side wall 9 can be attached in the manner shown in FIGS. 16 and 17 . In the embodiment shown, the side walls 9 are made by injecting elastomeric material into another mold cavity 53, said side walls being made in the mold cavity 53, and then laterally attached to the On the carcass structure 2.

In the embodiment shown, each side wall 9 has a radial outer portion 9a and a radial inner portion 9b, both made of different elastic materials, joined together by overmolding. To this end, the mold 53 essentially has an outer half 53a and a pair of inner halves 53b, the two inner halves being interchangeable, only one being shown in the figures.

First, the outer half 53a is engaged with a first inner half (not shown) to define a first cavity of the mold 53, in which the radial direction of the side wall 9 is formed by injecting a first elastic material. The exterior of 9a. The first inner half of the mold 53 is then replaced by a second half 53b shaped to be inside the second inner cavity of the mould, the portion corresponding to the aforementioned radially outer portion 9a already defined. The second mold closure is to make the radial inner portion 9b, which is formed by injecting the second elastic material.

Each of the sidewalls 9 formed in the above-described manner can be attached laterally to the carcass structure 2, as described above.

The tire 1 thus produced can be removed from the annular table 11 to undergo a vulcanization step which can be carried out in any known and conventional manner.

According to another possible embodiment, before the vulcanization step, an air tube with a closed annular section is associated with the tire 1 in addition to or instead of the liner 10, which air tube is removed after the tire has been removed from the annular table 11. Insert into carcass 2. The air tube, which is not shown in the accompanying drawings, is inflated after the tire is placed in the vulcanization mold to provide the required internal pressure to ensure that the tire is well attached to the side wall of the mold, in particular, attached In the mold portion there are longitudinal and transverse grooves 8a defining the tread pattern.

According to another advantageous characteristic of the invention, during the vulcanization step, the carcass ply 3 and the belts 6, 7 are subjected to a stretching step in order to generate a pretension to inflate the tyre, the circumference measured on the mid-section plane X-X of the tyre. The linear elongation in direction is, for example, between 2% and 5%. This stretching step can be achieved by the inflation pressure of the above-mentioned air bag, or by using other types of inflatable lumens in the vulcanization device.

The invention achieves important benefits.

Said tire is obtained by forming the different elements directly on the annular table, so that the tire is produced step by step, in any case the elements are formed in close proximity to the annular table. In this way, the problems associated with the preparation, storage and management of semi-finished products, which are common in traditional manufacturing methods, are eliminated.

In particular, it should be noted that the formation of the carcass layer in such a way that the belt-shaped element consisting of several strands of core is laid within a layer of elastic material can yield important advantages. Firstly, the preparation time per carcass layer can be substantially reduced compared to the aforementioned US Patent No. 5,453,140, since as many linear elements as possible can be laid simultaneously within the belt-shaped elements 13 . The use of strip-shaped elements 13 also eliminates the need for laying the liner 10 on the annular table as before. The elastic material layer 13b used in forming the strip-shaped element 13 ensures that the element 13 is effectively attached to the annular table 11, thereby ensuring a stable positioning of the laying sections 23, 24.

The positional accuracy of the laying section and the integrated linear element is further improved, since the strip-shaped element has an important structural consistency, which makes vibrations and similar vibration effects transmitted by the laying device 28 insensitive. In this regard, it should be noted that, as described in US Patent No. 5,453,140, its individual linear elements make it difficult to obtain accurate laying of the individual segments, since the segments are precisely subjected to vibrations and/or vibrations during the laying step.

In addition, the simultaneous laying of several linear elements according to the invention allows the operating speed of the laying device 28 to be lower than that required for laying the individual segments separately, which also has advantages in terms of working accuracy, without thereby affecting the production rate.

Furthermore, the direct laying of the strip-shaped elements in the direction of the crown on an annular platform whose contour essentially corresponds to that of the product tire achieves a density not achievable by methods known in the art in which the carcass plies First laid on a cylindrical barrel and then formed toroidally, this thins the core of the carcass ply laid on the crown of the product tire.

In addition, the strip-shaped element can be stably fixed on the annular table by the vacuum generated by the possible suction line 28 , which is not possible with known methods in which individual wire segments are laid.

The oblique arrangement of the sides 23a, 23c, 24a, 24c facilitates the stretching during the stretching step of the tire, which is forcibly stretched during the vulcanization process. During this step, the sides tend to be inclined in the radial plane of the tyre, together with the crowns 23b, 24b extending between them.

The overlapping of the sides near the axis of rotation of the tire greatly increases the structural strength of the tire near the beads, where greater structural strength is usually required.

Attention should also be paid to the initial structural characteristics of the inextensible annular structure 4 arranged at the blank holder. In particular, due to the presence of the circumferentially inextensible annular insert 32 and the conventional blankholder core 31, the tendency of the blankholder to rotate under the action of the sliding thrust can be effectively prevented. In the prior art, this phenomenon can lead to the tire slipping off the respective safety bumps provided on the hub, especially when the tire is subjected to a sliding thrust in a partially deflated state. By providing the annular insert 32, this disadvantage is eliminated, and the tire can be used even in a practically completely deflated state, without unwanted movement of the bead from the seat.

Behavior of the tire beads during slippage of a tire according to the invention is shown in Figure 19, which shows a half cross-section of a tire 1 in relation to a standard mounting hub 54, at each tire bead, The hub 54 has a bead seat 55 axially delimited by a flange 56 defining the outer edge of the hub and a safety bead 57 . For the sake of clarity, the portion of the tire 1 indicated by the dot-dash line has been omitted.

It is easy to see from this figure that the presence of the inextensible annular insert 32 prevents the bead of the tire from rotating about the safety bead 57 provided on the hub 54 under the action of the sliding thrust N directly parallel to the tire axis of rotation. In this case, the sliding thrust N transmitted along the carcass layer 3 to the blankholder edge 31 can be decomposed into a radial component force N1 and an axial component force N2, and the radial component force N1 tends to make the blankholder leave the blankholder seat 55 , and is offset by the circumferential inextensibility of the annular structure 4, while the axial component N2 tends to make the pressure edge abut against the circumferential flange 56 to ensure its stable positioning.

In this way, a tire with bead produced according to the invention can withstand the so-called "J-curve test" up to an inflation pressure of 0.5 bar, without the bead leaving its seat, whereas in the prior art, at pressure Tires that do not counteract bead displacement at less than 0.8-1.0 bar are also considered acceptable.

It should also be noted that the annular insert 32 provides further structural protection to the tire at the beads.

Claims (38)

1. A tire manufacturing method, comprising the following steps: Prepare a carcass structure (2); Attaching a belt structure (5) to the carcass structure (2) along the outer side of the carcass structure in the circumferential direction; Attach the tread belt (8) on the belt structure (5) along the outer side of the belt structure (5); attaching at least one pair of sidewalls (9) to the carcass structure (2) at laterally opposite positions of the carcass structure (2); The tire (1) obtained by vulcanization is characterized in that the manufacture of the carcass structure (2) includes the formation of at least one carcass layer (3), the steps of preparing the carcass layer (3) are as follows: Prepare at least one continuous strip-shaped element (13) comprising several longitudinally parallel linear elements (13a) at least partially coated with at least one layer of elastic material ( 13b) raw materials; The strip-shaped element (13) is laid on the annular table (11) with alternate laying sections (23, 24), and the transverse cross-sectional profile of each laying section (23, 24) around the annular table (11) is U in nature. Extended in shape to form two side portions (23a, 23c, 24a, 24c) and a crown portion (23b, 24b), the two side portions (23a, 23c, 24a, 24c) are axially spaced from each other extending in a plane substantially perpendicular to the axis of rotation of the annular table top (11), the crown (23b, 24b) extending radially outwardly between the two sides (23a, 23c, 24a, 24c); The crowns (23b, 24b) of each laying section (23, 24) are laid side by side continuously along the circumferential direction of the annular platform (11), wherein the side parts (23a, 23c, 24a of each laying section (23, 24) , 24c) overlaps with a side portion of at least one subsequent laying section. 2. A method according to claim 1, characterized in that the mutual overlapping relationship of the sides (23a, 23c, 24a, 24c) results in mutual convergence in the direction of the geometric axis of rotation of the annular table (11). 3. The method according to claim 1, characterized in that: the mutual overlapping relationship of the sides (23a, 23c, 24a, 24c) of each laying section (23, 24) is gradually reduced, and the maximum value is located on the side. The radially inner end of the crown and the transition zone between said side and the crown (23b, 24b) has zero overlap. 4. A method according to claim 1, characterized in that the sides (23a, 23c, 24a, 24c) in superimposed relationship remain connected at the curved end region (25) where the strip-shaped The element (13) itself is folded. 5. The method according to claim 1, characterized in that: the circumferential spacing of each laying section (23, 24) successively laid on the annular platform (11) is the width of the strip-shaped element (13). 6. The method according to claim 1, characterized in that: the circumferential spacing of each laying section (23, 24) successively laid on the annular platform (11) is a multiple of the width of the strip-shaped element (13). 7. 2. A method according to claim 1, characterized in that the width of the strip-shaped element (13) is measured in the mid-section as a submultiple of the circumference of the annular table (11). 8. The method according to claim 1, characterized in that manufacturing said at least one carcass layer (3) further comprises subsequent pairs of sides (23a, 23c, 24a, 24c) A step of stretching the strip-shaped elements (13) to form a region of greater width near the circumferential inner edge of the carcass structure (2). 9. 8. A method according to claim 8, characterized in that said stretching step is performed on the strip-shaped element (13) during the laying step by applying a stretching action to the strip-shaped element upstream of the annular table (11). 10. 8. A method according to claim 8, characterized in that, during said stretching step, the linear elements (13a) of the strip-shaped elements (13) are also simultaneously moved away from each other. 11. method as claimed in claim 1, characterized in that: in the laying step, at least one laying section comprising the initial end of the strip-shaped element remains on the annular table (11) by the action of suction produced by the annular table itself . 12. The method according to claim 1, characterized in that forming each laying section (23, 24) comprises the following steps: Guide strip-shaped elements (13) on the distribution element (22) movable around the transverse cross-sectional profile of the annular table (11); displacing the distribution element (22) in a direction substantially radially away from the geometric axis of rotation of the annular table (11) to form the first side (23a, 24a) of the laying section (23, 24) of the strip-shaped element (13) ); rotating the annular table (11) relative to the distribution element (22) by an angular step corresponding to half the distribution pitch of the laying sections (23, 24), simultaneously forming said first side portions (23a, 24a ); displacing the distribution element (22) in a direction substantially parallel to the geometric axis of rotation of the annular table (11) to form the crowns (23b, 24b) of the laying segments (23, 24) of the strip-shaped element (13); moving the distributing element (22) substantially radially close to the geometric axis of rotation of the annular table (11) to form the second side (23c, 24c) of the laying section (23, 24) of the strip-shaped element (13) ); The annular table (11) is rotated by said angular step relative to the distribution element (22) while simultaneously forming said second side portions (23c, 24c). 13. The method according to claim 12, characterized in that, during the formation of the first side (23a, 24a) of each laying section (23, 24), the first side of the already formed laying section is carried out The step of retaining the strip-shaped element (13) at the curved region (25) formed between the upper portion and the second side portion (23a, 24a). 14. method as claimed in claim 13, characterized in that: the retaining step of the strip-shaped element (13) is carried out in such a way that after the distribution element (22) is radially close to the geometric axis of rotation of the annular table (11) , along the second side portion (23a, 24a) retaining element (26) is provided, like this, band-shaped element (13) turns back around retaining element (26), thereby, because distribution element (22) is far away from annular table top radially (11) to form the bending zone (25). 15. The method according to claim 14, characterized in that, after starting to form the crown (23b, 24b) of the laying section (23, 24) in preparation, the retaining element (26) is moved axially ) to disengage. 16. A method according to claim 1, characterized in that the step of abutting said side portions (23a, 23c, 24a, 24c) of the laying section against the side walls of the annular table (11) is also carried out. 17. 16. A method according to claim 16, characterized in that the abutting step is repeated for the first and second sides (23a, 23c, 24a, 24c) of two consecutive laying sections (23, 24). 18. A method according to claim 1, characterized in that forming the carcass structure (2) further comprises the step of attaching at least one inextensible annular structure (4) close to the The area of each circumferential inner edge of the carcass layer (3). 19. The method according to claim 18, characterized in that forming the carcass structure (2) further comprises the step of turning back the sides (23a, 23c, 24a, 24c) flashing. 20. A method according to claim 1, characterized in that forming the carcass structure (2) further comprises the step of forming the second carcass layer in the same manner as the first carcass layer (3). twenty one. A tire manufacturing method, comprising the following steps: Prepare a carcass structure (2); Attaching a belt structure (5) to the carcass structure (2) along the outer side of the carcass structure in the circumferential direction; Attach the tread belt (8) on the belt structure (5) along the outer side of the belt structure (5); attaching at least one pair of sidewalls (9) to the carcass structure (2) at laterally opposite positions of the carcass structure (2); The tire (1) obtained by vulcanization is characterized in that the steps of forming each inextensible annular structure (4) are as follows: Laying at least one linear element as concentric coils (32a) in a mold cavity (34) to form a circumferentially inextensible annular insert positioned on a side substantially parallel to the carcass layer (3) ; positioning an annular anchoring element (31) within the mold cavity (34) axially adjacent to the circumferentially inextensible annular insert (32); The raw material of elastic material is injected in the mold cavity (34) to form a pouring body (33), which is tightly combined with the annular anchoring element (31) and the circumferentially inextensible annular insert ( 32). twenty two. The method according to claim 21, wherein said laying step is conveniently carried out before the step of dipping in rubber liquid, and in the step of dipping in rubber liquid, said linear element is laid with at least one layer of raw material of elastic material. twenty three. The method according to claim 21, characterized in that: there may also be such a step, that is, by magnetic means, the circumferentially inextensible annular insert (32) is retained at a predetermined position in the mold cavity (34) superior. twenty four. 21. A method according to claim 21, characterized in that the injection of the raw material of the elastic material takes place through at least one circumferential inlet or hollow channel (35) communicating with the mold cavity (34). 25． A tire manufacturing method, comprising the following steps: Prepare a carcass structure (2); Attaching a belt structure (5) to the carcass structure (2) along the outer side of the carcass structure in the circumferential direction; Attach the tread belt (8) on the belt structure (5) along the outer side of the belt structure (5); attaching at least one pair of sidewalls (9) to the carcass structure (2) at laterally opposite positions of the carcass structure (2); The tire (1) obtained by vulcanization is characterized in that: attaching the belt structure (5) comprises the steps of: forming at least one continuous strip (36) comprising at least one layer of raw material of elastic material (36b) at least partially comprising several longitudinally parallel cores (36a); cutting said continuous strip (36) at a predetermined angle relative to the longitudinal direction to form a strip segment (42) having a predetermined width when measured perpendicular to the cutting direction; Laying strip segments (41) continuously in circumferential alignment on the carcass structure (2) to form at least one first continuous strip (6) having said core (36a), the core (36a) is disposed transversely at an oblique angle corresponding to the cutting direction of said strip segment (42). 26． A method according to claim 25, characterized in that, before said cutting step, the continuous strip (36) is subjected to a calendering step so that the circumferential dimensions of said strip segments correspond to the circumferential dimensions of the strip (6) approximation of . 27． The method according to claim 25, characterized in that: attaching the belt structure (5) further comprises the step of forming at least one second belt (7) by winding at least one continuous linear element (44) The coils are arranged in a parallel relationship in the axial direction and extend in the circumferential direction relative to the first belt (6). 28． 27. The method according to claim 27, characterized in that the coils formed by winding the elongated element (44) have a variable distribution distance between each other along the axial direction. 29． 28. A method according to claim 28, characterized in that the axial distribution pitch near the mid-section plane (X-X) of the tire (1) is greater than the distribution pitch of the two side edges of the belt structure (5). 30． The method according to claim 1, characterized in that: attaching the tread belt (8) comprises the steps of: stacking at least one layer of continuous elastic material (49) raw materials along the circumferential direction of the belt structure (5) to form Several radially stacked rings (S). 31． 30. A method according to claim 30, characterized in that said continuous layer of elastic material (49) is produced simultaneously with the attachment to the belt structure (5). 32． A method as claimed in claim 30, characterized in that it further comprises the step of gradually reducing the width of the layer of elastic material (49) while the tape-wound structure (5) is wound in a ring shape (S). 33． A method according to claim 1, characterized in that each said side wall (9) is formed by injecting an elastic material into a mold (53). 34． The method according to claim 33, characterized in that forming each side wall (9) comprises the steps of: injecting a first elastomeric material into a first cavity formed in said mold (53) to form the radially outer portion (9a) of the side wall (9); forming a second mold cavity within the mold (53), which partially defines the radially outer portion (9a) of the side wall (9); A second elastomeric material is injected into the second cavity of said mold (53) to form the radially inner portion (9b) of the side wall (9). 35． The method according to claim 1, characterized in that: before forming the carcass layer (3), the step of laying at least one layer of airtight elastic material or liner ( 10). 36． method as claimed in claim 35, characterized in that: the step of laying is carried out in such a way that at least one strip (12) of airtight elastic material is wound into rings, each ring along the transverse cross-sectional profile of the ring table (11) In a parallel relationship. 37． The method according to claim 1, characterized in that: before the vulcanization step, the following steps are carried out: Take off the tire (1) from the annular table (11); Insert the air tube into the carcass structure (2). 38． A method according to claim 1, characterized in that in said vulcanization step said carcass layers (3) and belts (6,7) are subjected to a stretching step in order to generate tension in the tire to inflate the linear shape of the tire The elongation is between 2% and 5%.

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